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Detailed kinetics of titanium nitride synthesis
Author(s) -
Rode Hilmar,
Hlavacek Vladimir
Publication year - 1995
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690410219
Subject(s) - titanium nitride , activation energy , tin , thermodynamics , materials science , thermogravimetric analysis , isothermal process , reactivity (psychology) , rate equation , particle size , reaction rate , titanium , kinetics , analytical chemistry (journal) , chemistry , nitride , nanotechnology , metallurgy , organic chemistry , catalysis , medicine , physics , alternative medicine , layer (electronics) , pathology , quantum mechanics
A thermogravimetric analyzer is used to study the synthesis of TiN from Ti powder over a wide range of temperature, conversion and heating rate, and for two Ti precursor powders with different morphologies. Conversions to TiN up to 99% are obtained with negligible oxygen contamination. Nonisothermal initial rate and isothermal data are used in a nonlinear least‐squares minimization to determine the most appropriate rate law. The logarithmic rate law offers an excellent agreement between the experimental and calculated conversions to TiN and can predict afterburning, which is an important experimentally observed phenomenon. Due to the form of the logarithmic rate law, the observed activation energy is a function of effective particle size, extent of conversion, and temperature even when the intrinsic activation energy remains constant. This aspect explains discrepancies among activation energies obtained in previous studies. The frequently used sedimentation particle size is a poor measure of the powder reactivity. The BET surface area indicates the powder reactivity much better.